Piston ring device



April 21, 1942. BQWERS 2,280,743

PISTON RING DEVICE Filed July 5, 1941 Patented Apr. 21, 1942 PISTON RENGDEVICE'. Thom-A. Bowers, Mattapolsett, Mass, asslgnor to Powerltesearch Corporation, Boston, Mass, a corporation of Massachusetts g "Application July 5; 1941, Serial No.401,18'1

5'Claims.

This invention relates to piston ringsand in general to the .type of piston ring disclosed. in my earlier Patent No. 2,224,338, issued December 10, 1940, and my copending application Ser. No. 354,839, filed August 30, 1940.

The principal object of the invention is to improve piston rings and to devise of sheet materials piston ringstructuresof the same generalcharacter as those described in the. above referred to applications, in which a plurality of segments are arranged in annular rows and the segments are supported in circumierentially movable relation to one another. Another object of the invention is to devise a piston ring having a novel.

arrangement of segments and connecting portions forthe segments, with the objectinview of improving'the sealing character of such rings. Another object of the invention-is to provide an improved piston ring of the type in which a strip of piston ring material .is bent longitudinally of itself. Still other objects are to. provide piston ring structures whichv are=adapted to manufaoture by tool machinery which can be .quickly I made and whichare generally simple, cheaper, and more efiicient in operation.

The nature of the invention and its objects will be more fully understood from the following description of the drawing and discussionrelating thereto. r

In the accompanying drawing:

Fig. 1 is a fragmentary plan view illustrating a step in the method of making the ring of thein vention Fig. 2 is a diagrammatic view partly in cross section illustrating another step in the'method referred to;

Fig. 3 is a fragmentary plan view. illustrating" still other steps in the method; I

Fig. 4 is a cross section taken "on the line 4 4 of Fig. 3.

view of a finished ring of the invention;

Fig. 5 is an enlarged fragmentary perspectivev Fig. 6 is a fragmentary plan view of a modifi-' cation of piston ring;

Fig. '7 is an enlarged fragmentary perspective view of a ring similar to that shown in Fig. 6;

Fig. 8 is a plan view of a complete ring similar to the rings shown in Figs. 6 and '7; and

Fig. 9 is an enlarged detail view partly in cross section illustrating another modification of pis- 1 ton ring.

In the construction shown in Figs. 1-5 inclusive, numeral I indicates a strip of sheet material employedin making the ring of the invention. The sheet is of a resilient character and tially movable may be, for examplepof spring steel, anallo or other'suitable material.

In my earlier patent above noted, I havesde-i scribed apiston-ring constructed from a resilient metal. strip which is formed with. transversely. disposed overlapping openings, and'is folded longitudinally of itself to provide spaced apart outer peripheral edges for meteringoil; The'overlap' ping openings in the strip, define circumferen- U-shaped connecting portions.

.The relatively open formation of the .U-shaped. connecting portions especially it provides for theconnecting portions being Warped. or.- twisted in directions circumferentially of the ring to close the transverse openings. Since the. connecting portions are constituted of a resilient metal, they tend to spring back to their normal bent' position, thereby exerting a useful flexibility and wall pressure in the ring as a whole. Theability of the connecting portions to become'thus warped and create resiliency is developed toa relatively greater extent by the openformation noted, as compared to a formation, for example, where the 'connectingportions might be completely. doubled over. a

According to the present invention, I provide a piston ring of a somewhat similartype inwhich a plurality of connected segments are secured together inannula'r rows as may be obtained, for

example, by folding a strip of resilient sheet-- metal longitudinally of itself. I further provide for the segments. being arranged in superimposed relation to provide a substantially solid.

outer peripheral ring portion, and .Icombine with thelsubstantially solid outer'ring periphery, connecting portions of an? open or substantially U-shaped formation which are adapted'to be warped or twisted in .a direction circumferen vtially of the ring and provide relatively great resiliency. Y

Referring in detail to Figs. 1-6 inclusive, I have illustrated one method of making a ring or this general character. The strip l is formed, by

some suitable means as punching, with openings 2 which leave intermediate portions of the strip hereinafter referred to as webs or connecting portions 3.

The punched strip is. subjected to aforming operation, as for example rolling, which thins the connecting portions 3 relative .to the edges l and 5. This operation has been diagrammatically il-' lustrated in Figs. 2 in which is shown a base 61 which supports the resilient strip I and over which is applied a roll I.

segments and substantially.

The rolled strip l is bent along lines of bending which intersect the connecting portions 3 so as to arrange them in a generally open or U-shaped manner as has been illustrated in Figs. 3 and 4. The edges 4 and 5 of the strip, due to their relatively greater thickness, become superimposed one upon another to form a substantially solid annular section connected by the open connecting portions. The strip is further bent to form an annular body in some suitable manner, as for example by passing it through complementary circular die members.

The strip in the circular form noted is cut to provide openings 8 and 9 which extend transversely inward from its opposite edges. These openings 8 and 9 connect with the openings 2 be-' tween the connecting portions 3 in an alternate member so that the openings 8 in the bent posi- 7 tion of the strip occur in staggered relation with clude two connecting portions 3. This provides for the connecting portions, included by any one of the segments at one edge of the ring, being attached to separate segments at an opposite edge of the ring. The relatively thickeredges l and 5 of thestrip l, in the folded position of thering illustrated in Figs. 3, 4 and 5, extendbeyond the connecting portions 3 in a; direction axially of the ringxand thus allow theconnecting portions 7 3 to occur in anopen .or substantially U-shaped manner whenqthe edges l and 5 are folded over upon one another.

An important feature of the ring consists in the combination of the relatively thick segments I 0 and II disposed one against another, with a plurality of open or substantially U-shaped connecting portions. The relatively thick segments I0 and 1";1310Vid6 a solid outer peripheral portion for the-ring which is highly desirable in respect to wearing ability and resistance to passageof .combustiongases. radially therethrough. At the same time the open formation of the webs allows a ,maximumof warping or distortion to occur and thus insures highly developed resiliency inthegring. I l

It willbeobserved that the openings 8 are disposed in staggered relation with respect to the openings 9 so as'to seal the ring with respect to passage of gases axially therethrough. When the ring, is installed in a piston and engaged against a cylinder wall, the openings 8, therefore, become completely sealed with respect to gas seeking to pass from the head of the cylinder downwardly by the ring. The openings 9 while they connect from the back of the piston ring groove to points between the piston and the cylinder, andbelow the ring, are preferably formed sufficiently small to retain films of oil which are adapted to resist radial passage of gases and allow the ring to function as a substantially gas-proof member.

with respect to the openings l5. The'offset arrangement of the openings provides overlapping portions in adjacent segments. Similarly, the' completely gas-tight sealing structure adapted to'resist passage of gas both axially and radially therethrough, and independently of any use of oil films such as described in connection with the ring of Figs. 1-5 inclusive. The advantages pointed out in the previous ring modification with respect to the solid outerperlpheral ring portion being combined with open webs adapted to efficient warping or twisting to develop resiliency, is maintained in the ring modification of Figures 6-8 inclusive. I may desire to incorporate the overlapping segment construction in a ring in which the connecting portions are completely doubled over upon one another and the edges are not relatively thicker than the connecting portions. V

In Fig. 9 I have illustrated still another modification of ring in which segments 29 and H are connected together by open connecting portions 22. The segments 28 have segments 23, separately attached thereto as by means of rivets 24.

and similarly the segments 2! have segments 25v separately attached by means of rivets 26.

The attachment of separate pieces of material to segments is illustrative of other means of obtaining a ring in which the outer segment portions extend axially beyond the open connecting portions and in which a substantially U-shaped formation of the connecting portions is preserved. A ring of the character noted may be formed in various other ways, as, for example by cutting the segments out of solid ring bodies or by assembling a plurality of segments separately upon annularly arranged connecting portions of open formation, or in other ways.

It will be observed that the ring of the invention combines novel outer peripheral ring portions which are substantially continuous with inner peripheral portions. The inner peripheral portions are open and are of a generally U-shaped formation adapted to being warped or distorted to develop high resiliency. The outer peripheral ring portions are arranged in superimposed rela- I tion to provide desirable sealing effects. Also a If desired, however, I may provide for sealing action by the ring, with respect to gas directed radially therethroug h, independently of oil films. For example, in Fig; 6 I have illustrated a ring having relatively thick segments 12 and I3 and open, substantially U-shaped connecting portions H. These segments [2 are separated by outer openings 15, and inner openings 16 offset novel overlapping segment construction has been disclosed.

While I have, shown a preferred embodiment of the invention, it should 'be understood that various other changes may be resorted to, in keeping with the spirit of the invention as defined by the appended claims.

I claim:

1. .A radially and circumierentially flexible piston ring comprising a plurality of segments of piston ring material contiguously arranged to form annular rows, web portions for connecting segments of one of the rows in superimposed relation with respect to segments of another of the said rows, said web portionsextending radially inward of the ring and being circumlerentially spaced apart, each of said rows of segments hav-- ing radially disposed openings occurring between constituent segments, said openings being offset to provide portions in adjacent segments which overlap one another, the openings occurring between segments of one of the said rows being ar ranged in staggered relation with respect to the openings occurring between segments of the other of the said rows, and each of said webs having axially spaced-apart portions.

2. A circumferentially and radially flexible piston ring comprising upper and lower superimposed layers of sheet material, each of said upper and lower layers being separated by openings extending from the outer periphery of the ring in overlapping relation, said openings forming segments circumferentially movable with respect to one another, means for connecting segments of one of the said layers to segments of the other of the said layers, said connecting means having axially spaced-apart portions.

3. -A circumferentially and radially flexible piston ring comprising layers of sheet metal superimposed one upon another, connecting portions for the said layers, said connecting portions extending radially inward of the ring beyond the said layers in circumferentially spaced-apart relation, said layers having overlapping radial slots defining circumferentially movable segments, and parts of each of the connecting portions adjacent their points of meeting with the layers being spaced apart in a direction axially of the ring.

4. A flexible piston ring comprising upper and lower layers of sheet material superimposed one 5 upon another, means for connecting the said upper and lower layers together, each of said upper and lower layers being separated to form segments, the adjacent segments of the respective layers having portions which overlap one another 10 and presenting inner interstices and outer inter- A piston ring pri ing a plurality of Seg ments of piston ring material arranged in contiguous relation to form upper and lower annular rows, connecting portions for supporting segments of one of the rows in superimposed relation with respect to segments of the other of the rows, said segments constituting a substantially solid outer peripheral portion of the ring and said connecting portions having openings extending therethrough in a direction circumferentially of the ring to provide substantially U-shaped elements.

THOMAS A. BOWERS. 

